Shaft-hub connection for transmission

Abstract

The invention relates to a shaft-hub connection (10) for a planetary gear (2), comprising: an inner hub element (12); an outer hub element (14) drivingly connected to the inner hub element (12) via spline teeth (16) about a main axis of rotation (AR) and surrounding the inner hub element (12) at the outer circumference wherein the inner hub element (12) and the outer hub element (14) bear against each other via a pair of axial contact surfaces (20, 22). The invention also relates to a transmission (2) having a shaft-hub connection (10). The transmission (2) may be used in a drive train (76) of a wind turbine (70). In the aforementioned shaft-hub connection (10), the lubricating oil does not have to work against centrifugal forces to reach the axial contact surface as in a conventional solution for lubricating the axial contact surface.

Description

Technical Field

[0001] The invention relates to a shaft-hub connection for a planetary gear, comprising an inner hub element and an outer hub element, which is driven by a splined tooth system around a main rotation axis A. R The outer hub element is connected to the inner hub element and surrounds the inner hub element at the outer circumference, wherein the inner hub element and the outer hub element abut against each other via a pair of axial contact surfaces. The invention also relates to a transmission device having a shaft-hub connection. Background Art

[0002] Wind turbine transmissions typically include planetary transmissions that can be designed with one or more planetary stages. The teeth of a planetary transmission typically have a helical design. The helical teeth induce axial forces within the planetary stage, which must be supported in the subsequent stages involved in the force flow. Planetary transmissions and stages have different configurations. In a first configuration, for example, in a planetary stage, the output can be via a sun gear or a corresponding sun shaft, which is mounted radially relative to the planetary gears in the running teeth and radially relative to the subsequent components (e.g., the hollow hub element of a spur gear stage) in the splined teeth. In this case, the sun shaft is structurally an inner hub element, while the hollow hub element is an outer element and can be designed as a hollow shaft. Configurations in which the outer hub element directly drives the downstream generator (i.e., without an intervening spur gear stage) are also possible. In another configuration of the planetary stage, the inner and outer hub elements are arranged so that, for example, the sun shaft or sun gear of the planetary stage is configured as the outer hub element, and the inner hub element is designed to drive the hollow shaft of the subsequent planetary stage. The inner hub element can be connected, for example, directly or indirectly in terms of drive to a planet carrier of a subsequent stage.

[0003] The axial mounting of a hub element for supporting axial forces introduced in the main force direction is usually achieved via an abutment shoulder of the hub element, which is supported against a corresponding abutment shoulder of the other hub element. In this case, the corresponding abutment shoulders contact each other via a pair of axial contact surfaces. The abutment shoulders can also be called shaft collars or shaft shoulders. Depending on the magnitude and displacement of the axial forces of the components involved, wear can occur on the axial contact surfaces, which wear can in principle be offset by oiling the axial contact surfaces during operation. One possibility is to guide oil in the axial direction through the spline teeth between the two hub elements and supply the oil to the axial contact surfaces. This involves a passive supply of oil, which is limited in particular under operating conditions at high speeds. Since the direct point of oil supply to the axial contact surface is in principle located radially outside the axial contact surface, the main centrifugal forces drive the oil outwards and prevent the oil from being able to be transferred radially inwards to the axial contact surface to a sufficient extent. DE 10 2013 217 950 A1 describes another option that addresses the aforementioned disadvantages of passive oil supply through pressure lubrication, actively delivering lubricating oil to the axial contact surfaces via oil guide channels. This type of pressure lubrication can be considered detrimental in terms of expenditure and costs. There is a continuing need to simplify and improve the oiling of axial contact surfaces. CN 102 312 928 A should also be mentioned as prior art. Summary of the Invention

[0004] The object of the present invention is to specify measures which allow simplified and improved oiling.

[0005] This object is achieved by a shaft-hub connection for a planetary transmission having the features of claim 1. Preferred configurations are specified in the dependent claims and in the following description and can each represent an aspect of the invention individually or in combination. If a feature is presented in combination with another feature, this serves only to simplify the presentation of the invention and is in no way intended to indicate that the feature in question cannot also be a development of the invention without the other features.

[0006] One embodiment relates to a shaft-hub connection for a planetary transmission, comprising an inner hub element, an outer hub element, which is driven by a splined tooth system around a main rotation axis A. R connected to the inner hub element and surrounding the inner hub element at the outer circumference, wherein the inner hub element and the outer hub element bear against each other via a pair of axial contact surfaces, wherein the inner hub element forms at least one oil channel for oiling the axial contact surfaces in the region of the axial position of the axial contact surfaces, the at least one oil channel opening radially in the axial contact surfaces via an outlet nozzle.

[0007] In the present case, the main axis of rotation A RThe axial direction is defined such that a corresponding radial direction is generated by the axial direction. Thus, the corresponding axial position of the axial contact surface and the corresponding axial position of the at least one radially extending oil channel of the inner hub element substantially coincide. Strict geometrical coincidence of the axial positions of the axial contact surface and the oil channel is not absolutely necessary.

[0008] Depending on the configuration, the outer hub element can be designed as a hollow shaft or sun shaft or sun gear. The spline teeth that connect the inner and outer hub elements to each other in a form-fitting manner for torque transmission are referred to as stub teeth. The stub teeth can be of a helical tooth design. The hub element can be mounted via a bearing arrangement, for example relative to a transmission housing structure, with one of the bearing arrangements being configured to absorb or support axial forces.

[0009] The oil channels are passage holes extending from the inner circumferential surface to the outer circumferential surface of the inner hub element. It's not absolutely necessary for the oil channels to have a circular cross-section; their cross-sections can also be elliptical, polygonal, or slot-shaped. The number of oil channels can vary depending on the application. Advantageously, the corresponding number of oil channels is evenly spaced around the circumference of the inner hub element.

[0010] The inner hub element, which is preferably hollow, can centrally house a conduit through which the electrical wires are routed. Between the conduit and the inner circumference of the hub element, a circumferential volume is provided in which the oil is retained or can flow during operation so that the oil is driven through the oil channel by centrifugal forces acting during operation.

[0011] In this configuration of the shaft-hub connection, the lubricant does not have to work against centrifugal forces to lubricate the axial contact surfaces, as is the case with conventional solutions for lubricating axial contact surfaces. Instead, the centrifugal forces facilitate the transfer of the oil to the axial contact surfaces. The service life of the axial contact surfaces can be extended by more targeted and improved radial introduction of lubricant into the axial contact surfaces.

[0012] In a development, it is particularly advantageous to facilitate the occupation of the oil by means of an oil channel which opens out in the form of a geometrical shape extending circumferentially on the inner peripheral surface of the inner hub element. The geometrical shape may be in the form of a recess, groove, shoulder or depression formed in some other way relative to the inner peripheral surface. The inner periphery of the hub element has a larger diameter at the base of the geometrical shape than at its adjoining parts. Due to the centrifugal forces which prevail during operation, the oil is collected particularly effectively via or in the geometrical shape and can also be retained there before flowing radially outwards from the geometrical shape through the oil channel in order to be transferred to the axial contact surfaces and to oil and lubricate the latter. The inner peripheral geometry does not require a structural weakening of the hollow shaft, since during operation the torque flow is already transferred to the hub element via the spline teeth in advance. The geometrical shape is not within the scope of the torque flow.

[0013] In a specific embodiment, since the axial contact surface of the inner hub element is formed on a radial shoulder of the hub element, in an advantageous embodiment, the oil channel can be open in the region of the radial shoulder. For example, the foot region can be provided as an open region. In this way, the oil can be easily centrifuged further radially outward by the centrifugal forces prevailing during operation, or driven outward over the radial shoulder, directly onto the axial contact surface or between the paired axial contact surfaces of the inner and outer hub elements.

[0014] In another preferred configuration, a seal is provided, disposed between the inner and outer hub elements, axially offset from the oil passage. Specifically, the seal is positioned so that the oil passage is located between the axial contact surface on one side and the seal on the other side, so that after the lubricating oil has exited the oil hole, it must flow over the axial contact surface. Sealing can be achieved, for example, via an O-ring or a plastic bushing inserted between the inner and outer hub elements.

[0015] In an advantageous embodiment of the axial contact surfaces, a surface profile is applied to at least one of these surfaces. This allows a certain amount of lubricating oil to remain in the oil sump as a reserve, which continues to provide lubrication even when the oil channel is refilled with lubricating oil. In this case, the surface profile can be formed such that at least one of the axial contact surfaces is provided with a central crown. Alternatively, the axial contact surfaces can also be tapered or positioned conically relative to one another.

[0016] In a first possible configuration, the radial shoulder or the abutment shoulder is formed integrally with the inner hub element, in particular in such a way that the hub element is machined at one end, for example by turning, and the radial shoulder extends between the machined diameter and the abutment diameter. This configuration is particularly advantageous if the main force direction, determined by the axial force, points towards the machined shaft end.

[0017] In another possible construction, the radial shoulder is formed by an abutment ring which is coaxially attached to the inner hub element at one end. In this case, the radial shoulder extends between the diameter of the shaft end and the corresponding larger diameter of the abutment ring. This construction is advantageous, in particular, if the main force direction determined by the axial force is oriented along the shaft, starting from the shaft end supporting the abutment ring. In terms of manufacturing, it can be provided that the abutment ring is held on the hub element via a threaded connection at one end. This multi-part arrangement leads to the advantageous possibility that the oil channel is formed by a recess extending radially on the end face of the hub element and / or on the end face of the abutment ring. Furthermore, it can be provided in this case that the oil channel and the recess surrounding the inner circumferential surface of the hub element are arranged in a separation plane between the hub element and the abutment ring, resulting in a further simplification in terms of manufacturing.

[0018] Furthermore, the object is achieved by a transmission for a wind turbine, comprising at least one planetary stage and an outer hub element, the outer hub element being transmission-connected to the at least one planetary stage, wherein at least one transmission connection between a plurality of planetary stages and / or between at least one planetary stage and the outer hub element is realized as a shaft-hub connection as described above. In particular, in this case, it can be provided that the subsequent planetary stage rotates faster than the preceding one.

[0019] The object is also achieved by a drive train for a wind turbine, comprising: a rotor shaft connected to a transmission in a torque-transmitting manner; and a generator connected to the transmission in a torque-transmitting manner, wherein the transmission is designed as described above. Furthermore, the planetary transmission and the generator can also be integrated with one another, that is, designed as a generator transmission.

[0020] Likewise, the basic object is achieved by a wind turbine comprising a nacelle on which a multi-blade rotor is rotatably arranged, said multi-blade rotor being connected in a torque-transmitting manner to a drive train, wherein the drive train is designed as described above.

[0021] Furthermore, the basic object is achieved by a data aggregate (computer program product) having a data package, combined in a common file or distributed in different files, for describing the three-dimensional design and / or interaction of all components provided in a shaft-hub connection as described above, wherein the data package is prepared for performing additive manufacturing of the components of the shaft-hub connection during processing by a data processing device, in particular by 3D printing using a 3D printer, and / or for simulating the functioning of the shaft-hub connection. This makes it possible to produce prototypes and / or computer-based simulations in order to study the functioning of the shaft-hub connection, identify problems in specific applications, and find improvements. The data model can also be suitable for simulating the fluid dynamic behavior of an operating medium (e.g. a lubricant). BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The invention will be explained below by way of example based on preferred exemplary embodiments with reference to the accompanying drawings, wherein the features presented below may in each case represent an aspect of the invention individually or in combination. In the drawings:

[0023] Figure 1 A first variant of the structural arrangement of the shaft-hub connection is shown;

[0024] Figure 2 Shown according to Figure 1 Details of the shaft-hub connection;

[0025] Figure 3 An alternative configuration of a shaft-hub connection is shown;

[0026] Figure 4 A second variant of the structural arrangement of the shaft-hub connection is shown;

[0027] Figure 5 Shown according to Figure 4 Alternative embodiments of variations of ;

[0028] Figure 6 shows a planetary transmission for use in a drive train of a wind turbine, and

[0029] Figure 7 A perspective view of a wind turbine is shown. DETAILED DESCRIPTION

[0030] Figure 1The structural arrangement of a possible configuration of a shaft-hub connection 10 is shown, details of which will be described below based on further figures. In the present case, the shaft-hub connection 10 is provided as a transmission connection between the planetary stage 6 and the spur gear stage 8. In the planetary stage 6, only the toothed engagement of the planetary gear carrier PT and the planetary gears PR with the inner hub element 12, which is designed as a sun shaft, is shown. In the spur gear stage 8, only the outer hub element 14, designed as a hollow shaft, and the gear ZR connected thereto for co-rotation are shown. If the spur gear stage 8 is not provided, the outer hub element 14 can be at least indirectly connected to a generator (not shown) in terms of transmission. The outer hub element 14 is mounted relative to the transmission housing GG via a bearing arrangement L1. Axial forces introduced into the outer hub element 14 can be supported via the bearing arrangement L1. The inner hub element 12 is mounted via spline teeth 16 and is transmission-connected to the outer hub element 14 arranged on its outer circumference. On the other hand, the inner hub element 12 is indirectly mounted in the transmission housing GG via the bearing arrangement L2 of the planetary gear carrier PT. The rotation of the two hub elements 12, 14 can be about the main rotation axis A. R The inner hub element 12 or the sun shaft is designed as a hollow shaft. In applications where the shaft-hub connection 10 is used, such as in planetary transmissions for wind turbines, this offers the possibility of allowing non-co-rotating threading tubes to run within the sun shaft 12. In the present case, the outer hub element 14 is also designed as a hollow shaft.

[0031] Figure 2 A detail of the shaft-hub connection 10 is shown, in particular the area where the axial forces acting on the inner hub element 12 are supported at the outer hub element 14. For the sake of clarity, the main direction of the axial forces is indicated by the arrow F. The axial forces are generated during operation by the planetary stages, which are designed with helical teeth. In the present case, the angle of the helical teeth is configured so that Figure 2 The main force direction F of the axial force in the illustration is oriented from left to right. The inner hub element 12 and the outer hub element 14 bear against each other via a pair of axial contact surfaces 20, 22. Axial forces introduced into the inner hub element 12 during operation are supported via the axial contact surfaces 20, 22. Despite the mating connection between the two hub elements 12, 14 via the spline teeth 16, relative movement occurs between the axial contact surface 20 of the inner hub element 12 on the one hand and the axial contact surface 22 of the outer hub element 14 on the other hand. To counteract the wear caused in this manner, or at least substantially reduce it, the axial contact surfaces 20, 22 are oiled.

[0032] The inner hub element 12 forms a radial shoulder 24 on which the axial contact surface 20 is located. The outer hub element 14 forms a corresponding radial shoulder 36 on which the axial contact surface 22 is located. The two axial contact surfaces 20, 22 are oriented relative to the main rotation axis A. R The inner hub element 12 conveniently extends in the radial direction. The position of the two radial shoulders 24, 36 results in the inner hub element 12 fitting into the outer hub element 14 in the same direction as the main force direction F. In order to axially support axial forces directed opposite to the main force direction F during reverse operation of the planetary stage, a retaining ring 38 is retained on the inner hub element 12. The retaining ring 38 supports the hub element 12 relative to the side of the radial shoulder 36 that is located at the rear relative to the axial contact surface 22.

[0033] The axial contact surfaces 20, 22 of the inner hub element 12 at the two radial shoulders 24, 36 are located relative to the main rotation axis A. R A plurality of circumferentially distributed, radially oriented oil channels 30 are formed in the region of the axial position of the hollow shaft 12 for lubricating the axial contact surfaces 20 , 22 . The oil channels 30 can be designed, for example, as oil holes with a circular cross-section. As can be seen, the oil channels 30 open radially outward via outlet openings 50 directly or at least approximately in the foot region 26 of the radial shoulder 24 . The oil channels 30 open radially inward at the inner circumferential surface 34 of the hollow shaft 12 , wherein it is particularly provided that the inner circumferential surface 34 of the hollow shaft 12 has a circumferential recess 32 into which the oil channels 30 open. The recess 30 ensures to a significant extent that, during operation and due to the prevailing centrifugal forces, lubricating oil is collected and driven outward via the oil channels 30 so that, after leaving the oil channels 30, it is transferred to the axial contact surfaces 20 , 22 and lubricates the latter. In order to ensure that the lubricating oil is supplied as fully as possible to the axial contact surfaces 20 , 22 after leaving the oil channel 30 , a seal 28 arranged between the inner peripheral surface of the radial shoulder 36 and the inner hub element 12 is advantageously provided.

[0034] Figure 3 An alternative configuration of the shaft-hub connection 10 is shown, which can be used in particular in the case of opposing main force directions F, which are present when the helical teeth are aligned with respect to the main axis of rotation A. R The outer hub element 14 is substantially aligned with the Figure 2, wherein in the present case the axial contact surfaces 22 are arranged on opposite axial sides. Accordingly, the radial shoulder 24 is formed by an abutment ring 40, which is attached to the inner hub element 12 at one end, wherein the abutment ring 40 and the hub element 12 are positioned coaxially relative to each other. The axial contact surface 22 of the hub element 12 is located on the end side 44 of the abutment ring 40 facing the radial shoulder 24. The abutment ring 40 is screwed to the axial end of the hub element 12 via a threaded connection 42 (the latter is only indicated). It can be seen that the oil channel 30 is formed by a radial recess 46 extending on the end side 44 of the abutment ring 40. Alternatively or additionally, the recess 46 can also extend on the end face 18 of the hub element 12, which is not shown in the present case. The oil channels 30 extend radially outwards to such an extent that they cover the axial contact surface 22 in the radial direction.

[0035] Figure 4 The structural arrangement of another configuration of a shaft-hub connection 10 is shown. In the present case, the shaft-hub connection 10 is provided as a transmission connection between a first planetary stage 4 and a second planetary stage 6, which are indicated in the present case by two arrows and the reference numerals 4 and 6. In the planetary stage 4, only the sun shaft SW is shown, wherein the sun shaft is designed as an outer hub element 14 of the shaft-hub connection 10. In the subsequent planetary stage 6, only the planet carrier PLT is shown schematically, wherein the planet carrier PLT is designed as an inner hub element 12 of the shaft-hub connection 10. As with the Figure 2 As described, a retaining ring 38 is provided which supports the hub element 12 relative to the side of the radial shoulder 36 which is located at the rear relative to the axial contact surface 22. In addition, with regard to the further structural arrangements of the shaft-hub connection 10 and with regard to the configuration of the pairs of axial contact surfaces 20, 22 and the oiling occurring radially from the inside, reference is made to Figures 1 to 3 Related description.

[0036] Figure 5 Shown Figure 4 In this case, the axial contact surfaces 20, 22 of the inner hub element 12 are formed on a second fixing ring 48 which engages circumferentially around the inner hub element 12. In addition, reference is also made here to Figures 1 to 4 Related description.

[0037] Figure 6 A purely exemplary planetary transmission 2 is shown, for example for a wind turbine. A first and a second rotating planetary stage 4, 6 and a spur gear stage 8 are accommodated consecutively in a transmission housing 3. In the present case, a shaft-hub connection 10 is provided as the transmission connection between the second planetary stage 6 and the spur gear stage 8. It can be provided that the second planetary stage 6 is designed to rotate faster than the first planetary stage 4.

[0038] Figure 7 shows an embodiment of a wind turbine 70. Wind turbine 70 includes a nacelle 71 on which a multi-blade rotor 72 is rotatably mounted. Multi-blade rotor 72 is connected to a main shaft 74 in a torque-transmitting manner, wherein main shaft 74 belongs to a drive train 76. Drive train 76 also includes a planetary gear 2 connected to main shaft 74 in a torque-transmitting manner. Planetary gear 2 has at least one planetary stage 6 and a spur gear stage 8 and is coupled to a generator 80. In the present case, a shaft-hub connection 10 is provided as the transmission connection between planetary stage 6 and spur gear stage 8, wherein shaft-hub connection 10 can be designed as described above.

[0039] Reference Signs List

[0040] 2 planetary transmission

[0041] 3 Transmission housing

[0042] 4-planet level

[0043] 6-planet level

[0044] 8 spur gear stages

[0045] 10 shaft-hub connection

[0046] 12 Hollow shaft

[0047] 14 hub element

[0048] 16 spline teeth

[0049] 18 end face

[0050] 20 Axial contact surface

[0051] 22 Axial contact surface

[0052] 24 Radial shoulder

[0053] 26 Foot area

[0054] 28 seals

[0055] 30 Oil channel

[0056] 32 recess

[0057] 34 Inner peripheral surface

[0058] 36 Radial shoulder

[0059] 38 fixing ring

[0060] 40 abutment ring

[0061] 42 threaded connection

[0062] 44 End side

[0063] 46 recess

[0064] 48 fixing ring

[0065] 50 outlet

[0066] 70 wind turbines

[0067] 71 Cabin

[0068] 72 Multi-blade rotor

[0069] 74 spindle

[0070] 76 Drivetrain

[0071] 80 generator

Claims

1. A shaft-hub connection (10) for a planetary transmission (2), comprising: Inner hub member (12), The outer hub element (14) is driven by the spline teeth (16) about the main rotation axis A R connected to the inner hub element (12) and surrounding the inner hub element (12) at its periphery, wherein the inner hub element (12) and the outer hub element (14) bear against each other via a pair of axial contact surfaces (20, 22), Its characteristics are: The inner hub element (12) forms at least one oil channel (30) for oiling the axial contact surfaces (20, 22) in the region of the axial position of the axial contact surfaces (20, 22), the at least one oil channel opening radially in the axial contact surfaces (20, 22) via an outlet nozzle (50).

2. The shaft-hub connection (10) according to claim 1, characterized in that The at least one oil passage (30) opens in a geometry extending circumferentially on the inner peripheral surface (34) of the inner hub element (12).

3. The shaft-hub connection (10) according to claim 1 or 2, characterized in that A plurality of oil passages (30) distributed in a circumferential manner are provided.

4. The shaft-hub connection (10) according to any one of claims 1 to 3, characterized in that In the inner hub element (12), the at least one oil channel (30) has a radial profile or a profile that is axially inclined with respect to the radial direction.

5. The shaft-hub connection (10) according to any one of claims 1 to 4, characterized in that The axial contact surfaces (20, 22) of the inner hub element (12) are formed on a radial shoulder (24) of the inner hub element (12), and the at least one oil channel (30) opens into the region (26) of the radial shoulder (24).

6. The shaft-hub connection (10) according to claim 5, characterized in that The radial shoulder (24) is formed by an abutment ring (40) which is coaxially attached at one end to the inner hub element (12).

7. The shaft-hub connection (10) according to claim 6, characterized in that The abutment ring (40) is retained at one end on the inner hub element (12) via a threaded connection (42).

8. The shaft-hub connection (10) according to claim 6 or 7, characterized in that The at least one oil channel (30) is formed by a geometric shape (46) which extends radially on the end face (18) of the inner hub element (12) and / or on the end side (44) of the abutment ring (40).

9. A shaft-hub connection (10) according to claim 2 and 5, 6 or 7, characterised in that The at least one oil channel (30) and the surrounding geometry are arranged in a separation plane between the inner hub element (12) and the abutment ring (40).

10. The shaft-hub connection (10) according to any one of claims 1 to 4, characterized in that The axial contact surfaces (20, 22) of the inner hub element (12) are formed on a retaining ring (38) engaged circumferentially around the inner hub element (12).

11. The shaft-hub connection (10) according to any one of claims 1 to 10, characterized in that A seal (28) is provided between the inner hub element (12) and the outer hub element (14), the seal (28) being axially offset from the at least one oil passage (30).

12. The shaft-hub connection (10) according to any one of claims 1 to 11, characterized in that A surface profile is applied to at least one of the axial contact surfaces (20, 22).

13. A transmission (2) for a wind turbine, comprising at least one planetary stage (4) and an outer hub element (14), the outer hub element (14) being transmission-connected to the at least one planetary stage (4), in, At least one transmission connection between a plurality of planetary stages and / or between the at least one planetary stage (4) and the outer hub element (14) is configured as a shaft-hub connection (10) according to one of claims 1 to 12.

14. A drive train (76) for a wind turbine (70), comprising a rotor shaft (74) connected to a transmission (2) in a torque-transmitting manner and a generator (80), wherein the rotor shaft (74) is connected to a transmission (2) in a torque-transmitting manner and the generator (80) is connected to the transmission (2) in a torque-transmitting manner, characterized in that The transmission (2) is designed as a transmission according to claim 12 or 13.

15. A wind turbine (70) comprising a nacelle (71) on which a multi-blade rotor (72) is rotatably arranged, the multi-blade rotor being connected to a drive train (76) in a torque-transmitting manner, characterized in that The drive train (76) is designed as a drive train according to claim 14.

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